kevin/linux
1
Fork 0
Code

mm/rmap: add hugetlb sanity checks for anon rmap handling

Browse Source 
Let's make sure we end up with the right folios in the right functions
when adding an anon rmap, just like we already do in the other rmap
functions.

Link: https://lkml.kernel.org/r/20231220224504.646757-7-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
David Hildenbrand 2023-12-20 23:44:30 +01:00 committed by Andrew Morton
parent 0c2ec32bf0
commit a4ea18641d
1 changed files with 6 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
mm/rmap.c
View File

@ -1262,6 +1262,8 @@ void page_add_anon_rmap(struct page *page, struct vm_area_struct *vma,
bool compound = flags & RMAP_COMPOUND;
bool first;
VM_WARN_ON_FOLIO(folio_test_hugetlb(folio), folio);
/* Is page being mapped by PTE? Is this its first map to be added? */
if (likely(!compound)) {
first = atomic_inc_and_test(&page->_mapcount);
@ -1343,6 +1345,7 @@ void folio_add_new_anon_rmap(struct folio *folio, struct vm_area_struct *vma,
{
int nr = folio_nr_pages(folio);
VM_WARN_ON_FOLIO(folio_test_hugetlb(folio), folio);
VM_BUG_ON_VMA(address < vma->vm_start ||
address + (nr << PAGE_SHIFT) > vma->vm_end, vma);
__folio_set_swapbacked(folio);
@ -2634,6 +2637,7 @@ void rmap_walk_locked(struct folio *folio, struct rmap_walk_control *rwc)
void hugetlb_add_anon_rmap(struct folio *folio, struct vm_area_struct *vma,
unsigned long address, rmap_t flags)
{
VM_WARN_ON_FOLIO(!folio_test_hugetlb(folio), folio);
VM_WARN_ON_FOLIO(!folio_test_anon(folio), folio);
atomic_inc(&folio->_entire_mapcount);
@ -2646,6 +2650,8 @@ void hugetlb_add_anon_rmap(struct folio *folio, struct vm_area_struct *vma,
void hugetlb_add_new_anon_rmap(struct folio *folio,
struct vm_area_struct *vma, unsigned long address)
{
VM_WARN_ON_FOLIO(!folio_test_hugetlb(folio), folio);
BUG_ON(address < vma->vm_start || address >= vma->vm_end);
/* increment count (starts at -1) */
atomic_set(&folio->_entire_mapcount, 0);